Sunshade assembly

ABSTRACT

A sunshade assembly includes a winding shaft, a sunshade curtain wound around the winding shaft, a pull rod connected to a sunshade curtain end distal from the winding shaft, and two guide rail units. Each guide rail unit includes a guide rail having a guide surface. A link unit includes a connecting shaft, and two guide wheels respectively attached to the connecting shaft. Each guide wheel has a rolling surface to roll on the respective guide surface. One of the rolling surface and the guide surface has a guide groove. The other of the rolling surface and the guide surface protrudes into the guide groove. A resistance unit provides a resisting force against rotation of the connecting shaft.

CROSS-REFERENCE TO RELATED APPLICATION

This application claims priority to Taiwanese Application No. 100223155, filed on Dec. 8, 2011.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The invention relates to a sunshade assembly, and more particularly to a sunshade assembly having guide rails and adapted for placement on an inside surface of a window of a vehicle or a building.

2. Description of the Related Art

Currently, there are various types of sunshade assemblies sold on the market, wherein a conventional track type sunshade assembly has two guide rails respectively disposed on two lateral sides of a sunshade curtain. In use, the sunshade curtain can be extended or retracted along the two guide rails. In order to adjust a sun shading area, manufacturers currently have developed various structures that allow users to freely pull and stop the sunshade curtain at any desired extended position so as to flexibly adjust an extent of sun shading. However, when the sunshade curtain is extended, the conventional sunshade assembly is limited by the structural design thereof, and thus, it is required to apply a pull force to the sunshade curtain at a central position of a free end of the sunshade curtain so as to smoothly extend the sunshade curtain along the guide rails. If the pull force is applied at a position deviating from the central position of the free end of the sunshade curtain, the pull force will be unevenly applied to the sunshade curtain, and the sunshade curtain tends to be obliquely taken up or stuck between the guide rails. Thus, the smoothness of take-up and extension of the sunshade curtain will be adversely influenced, and at the worst, extension of the sunshade curtain may not be possible, thereby causing inconvenience to users.

SUMMARY OF THE INVENTION

Therefore, an object of the present invention is to provide a sunshade assembly that can alleviate at least one of the aforesaid drawbacks of the prior art.

According to the present invention, a sunshade assembly includes two spaced-apart mounting seats, a winding shaft, a sunshade curtain, a pull rod, two guide rail units, a link unit, and a resistance unit. The winding shaft is mounted rotatably between the mounting seats. The sunshade curtain is extendably wound around the winding shaft. The pull rod is connected to one end of the sunshade curtain that is distal from the winding shaft. Each of the two guide rail units includes a guide rail that has a guide surface extending along the length of the guide rail. The link unit includes a connecting shaft mounted rotatably to the pull rod and having two opposite ends, and two guide wheels respectively attached to the two opposite ends of the connecting shaft. Each of the guide wheels has a rolling surface to roll on the guide surface of one of the guide rails. One of the rolling surface and the guide surface has a guide groove. The other one of the rolling surface and the guide surface protrudes into the guide groove. The resistance unit includes a base mounted to the pull rod and frictionally contacting the connecting shaft to provide a resisting force against rotation of the connecting shaft.

BRIEF DESCRIPTION OF THE DRAWINGS

Other features and advantages of the present invention will become apparent in the following detailed description of the preferred embodiments with reference to the accompanying drawings, of which:

FIG. 1 is a schematic view to illustrate the first preferred embodiment of a sunshade assembly according to the present invention in a take-up state;

FIG. 2 is an enlarged fragmentary perspective view illustrating cooperation among a link unit, a guide rail unit and a pull rod of the first preferred embodiment of FIG. 1;

FIG. 3 is an enlarged fragmentary, partly sectional view illustrating cooperation among the link unit, the guide rail unit and the pull rod of the first preferred embodiment of FIG. 1;

FIG. 4 is an enlarged fragmentary sectional view illustrating cooperation between the link unit and the guide rail unit of the first preferred embodiment of FIG. 1;

FIG. 5 is an enlarged fragmentary exploded view illustrating engagement between a resistance unit and the pull rod of the first preferred embodiment of FIG. 1;

FIG. 6 is an enlarged fragmentary sectional view illustrating assembly of the pull rod and the resistance unit of the first preferred embodiment of FIG. 1;

FIG. 7 is a schematic view to illustrate the sunshade assembly according to the first preferred embodiment of the present invention in an extended state;

FIG. 8 is an enlarged fragmentary perspective view illustrating cooperation among a link unit, a guide rail unit and a pull rod of the second preferred embodiment of a sunshade assembly according to this invention; and

FIG. 9 is an enlarged fragmentary, partly sectional view illustrating cooperation among the link unit, the guide rail unit and the pull rod of the second preferred embodiment of FIG. 8.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT

Before the present invention is described in greater detail, it should be noted that the same reference numerals have been used to denote like elements throughout the specification.

Referring to FIGS. 1 to 3, the first preferred embodiment of a sunshade assembly according to the present invention is illustrated. The sunshade assembly is adapted to be installed on an inside surface of a window of a vehicle or a building. In this embodiment, the sunshade assembly is disposed under a roof of the vehicle (not shown) for covering a sunroof. Alternatively, the sunshade assembly may be disposed on an inside surface of a vehicle door for covering a side window. Thus, the arrangement position and direction of the sunshade assembly according to the present invention can be adjusted based on an intended applied situation and are not limited to this preferred embodiment.

In this preferred embodiment, the sunshade assembly includes amounting unit 2, a sunshade unit 3, two guide rail units 1, a link unit 4, and a resistance unit 5.

The mounting unit 2 includes two spaced-apart mounting seats 21. Alternatively, the two mounting seats 21 may be integrally formed. Since the feature of this invention does not reside in the configuration of the mounting seats 21, which may be readily appreciated by those skilled in the art, details of the same are omitted herein for the sake of brevity.

The sunshade unit 3 includes a winding shaft 31 rotatably mounted between the mounting seats 21, a sunshade curtain 32 extendably wound around the winding shaft 31, and a pull rod 33 connected to one end 321 of the sunshade curtain 32 that is distal from the winding shaft 31. Preferably, the pull rod 33 is a hollow rod and extends along the width direction of the sunshade curtain 32. Preferably, the sunshade unit 3 further includes at least one resilient member (not shown) having two opposite ends. One of the opposite ends is fixed and the other of the opposite ends is connected to the winding shaft 31 so that the resilient member provides a resilient force to drive rotation of the winding shaft 31 to have a tendency towards the take-up state, i.e., the sunshade curtain 32 tends to be wound around the winding shaft 31 without an applied force.

In this embodiment, each of the guide rail units 1 includes a guide rail 12 having a guide surface 121 that extends along the length of the guide rail 12 and that has a guide groove 122. Preferably, each of the guide rail units 1 further includes an elongate frame 11 of substantially U-shaped cross section that has a main wall 111, and first and second sidewalls 112, 113 extending transversely and respectively from two opposite ends of the main wall 11 towards the other one of the guide rail units 1. The main wall 111 and the first and second sidewalls 112, 113 of each guide rail unit 1 cooperatively define a rail groove 114 having an opening end. The opening ends of the rail grooves 114 of the two guide rail unit 1 face each other. The guide rail 12 is lengthwise disposed on the first sidewall 112. Alternatively, the guide rail 12 may be disposed on the second sidewall 113 or each of the first and second sidewalls 112, 113 may be mounted with a respective guide rail 12. The frame 11 and the guide rail 12 of each of the guide rail units 1 may be integrally formed. Thus, the arrangement of the guide rail(s) 12 according to the present invention can be adjusted based on an intended applied situation and are not limited to this preferred embodiment.

The link unit 4 includes a connecting shaft 41 mounted rotatably in the pull rod 33 and having two opposite ends 410, 411, and two guide wheels 42 respectively attached to the two opposite ends 410, 411 of the connecting shaft 41 and respectively disposed in the rail grooves 114. Each of the guide wheels 42 has a rolling surface 421 to roll on the guide surface 121 and received in the corresponding the guide rail 12.

In this preferred embodiment, the guide groove 122 of the guide surface 121 of each of the guide rails 12 is designed by an arcuate groove-defining wall surface and the rolling surface 421 of the corresponding guide wheel 42 radially and outwardly protrudes into the guide groove 122.

The rolling surface 421 and the corresponding guide surface 121 maybe configured to have other shapes, such as trapezoid and complementary trapezoid contours, V and complementary V contours, U and complementary U contours, and complementary saw-toothed contours, as long as they mesh with each other.

When conducting adjustment of the sunshade curtain 32, the guide wheels 42 are together rotatable with the connecting shaft 41 and simultaneously moveable backward and forward along the guide rails 12. Since each of the rolling surfaces 421 protrudes into the corresponding guide groove 122, each of the guide wheels 42 can stably move along the corresponding guide rail 12 without swerving and the connecting shaft 41 can be moved in parallel with and relative to the winding shaft 31. Preferably, each of the guide wheels 42 may be formed into a caster or a friction roller that may be made of a flexible material selected from the group consisting of silicone, rubber and combinations thereof, while each of the guide rails 12 may be made from a material having a hardness higher than that of the flexible material, such as plastic. Alternatively, each of the guide rails 12 may be made of the flexible material and each of the guide wheels 42 may be made of the material having the hardness higher than that of the flexible material. The choices of the materials for making the guide wheels 42 and the guide rails 12 preferably complement each other, thereby reducing noise and providing a frictional resistance force when the sunshade curtain 32 is adjusted.

Further referring to FIG. 4 in combination with FIGS. 2 and 3, in this embodiment, the link unit 4 further includes two resilient press members 43 that respectively and resiliently press the guide wheels 42 against the guide surfaces 121. Preferably, each resilient press member 43 includes two bracket plates 431, a connecting section 432, and two resilient abutment sections 433. The two bracket plates 431 are sleeved onto the connecting shaft 41 on two opposite sides of a corresponding one of the guide wheels 42. The connecting section 432 interconnects ends of the bracket plates 431 between a corresponding one of the guide wheels 42 and the second sidewall 113. Each of the two resilient abutment sections 433 is curved outwardly from the bracket plates 431 in proximity to the connecting section 432 and presses resiliently the second sidewall 113 so that the corresponding one of the guide wheels 42 is pushed against the guide surface 121. However, the configuration of the resilient press members 43 is not limited to this embodiment. Each of the resilient press members 43 may include only one resilient abutment section 433 as long as the corresponding one of the guide wheels 42 is able to be pushed against the guide surface 121 and the guide wheel 42 is able to be stably moved along the guide groove 122.

Referring to FIGS. 5 and 6, in this embodiment, the resistance unit 5 is disposed in the pull rod 33, which is formed into a hollow rod, and includes a base 51 and a fastener 52. The base 51 is mounted in the hollow pull rod 33 and frictionally contacts the connecting shaft 41 to provide a resisting force against rotation of the connecting shaft 41. In this case, the base 51 includes two spaced-apart base walls 511, and a connecting wall 512 that interconnects the base walls 511 and that cooperates with the base walls 511 to define an open channel 513. The open channel 513 has an insert portion 514 proximate to the connecting wall 512, and an open portion 515 distal from the connecting wall 512. Preferably, the insert portion 514 has a configuration substantially corresponding to that of the connecting shaft 41.

The connecting shaft 41 is inserted through the insert portion 514. Moreover, the open portion 515 has a width narrower than that of the insert portion 514 such that the connecting rod 41 is limited in the insert portion 514 and sandwiched between the base walls 511. Each base wall 511 includes a threaded hole 516 communicating with the open portion 515. The threaded hole 516 is distal from the connecting wall 512.

The fastener 52 secures the base 51 to the pull rod 33. In this embodiment, the fastener 52 is configured as a bolt that extends through the pull rod 33 and that engages threadedly with the threaded holes 516 in the base walls 511 for securing the base 51 to the pull rod 33. In actual implementation, the number of the fastener 52 may be increased.

In this embodiment, the distance of the connecting wall 512 from the end 321 of the sunshade curtain 32 is longer than that of the fastener 52 that engages threadedly the base walls 511 from the end 321 of the sunshade curtain 32. Alternatively, the distance of the connecting wall 512 from the end 321 of the sunshade curtain 32 may be shorter than that of the fastener 52 that engages threadedly the base walls 511 from the end 321 of the sunshade curtain 32. Besides, the base 51 may be disposed outside the pull rod 33.

In use, the pull rod 33 can be pushed or pulled relative to the winding shaft 31. Therefore, the sunshade curtain 32 can be extended or retracted relative to the winding shaft 31 between an extended position shown in FIG. 7 and a take-up position shown in FIG. 1. After the sunshade assembly of this invention is assembled, the sunshade curtain 32 is at the take-up position. When the sunshade curtain 32 needs to be extended from the take-up position as shown in FIG. 1 to the extended position as shown in FIG. 7, the pull rod 33 is pulled to drive the connecting shaft 41 and the guide wheels 42 to move away from the winding shaft 31. Meanwhile, the sunshade curtain 32 can be extendably unwound between the guide rail units 1. When the sunshade curtain 32 needs to be retracted from the extended position as shown in FIG. 7 to the take-up position as shown in FIG. 1, the pull rod 33 is pushed to drive the connecting rod 41 and the guide wheels 42 to move towards the winding shaft 31, thereby winding the sunshade curtain 32 on the winding shaft 31.

Referring to FIGS. 1, 2, and 5, during movement of the sunshade curtain 32, the rolling surface 421 of each guide wheel 42 in the guide groove 122 of the corresponding guide rail 12 rotatably moves along the length of the corresponding guide rail 12, thereby driving the connecting shaft 41 to rotate in the same direction. Since the connecting shaft 41 is connected to the guide wheels 42, even when a pull force does not act on a central portion of the pull rod 33, an engaging mechanism between each of the guide rails 12 and the corresponding guide wheel 42 provides a stable and synchronous movement of each of the guide wheels 42 along the corresponding guide rail 12 without swerving therefrom. Accordingly, the engaging mechanism assures that the pull rod 33 smoothly and stably moves between the guide rail units 1 along a direction away from or toward the winding shaft 31. The engaging mechanism can avoid the pull rod 33 from extending obliquely that would result in impeding movement or being stuck between the guide rail units 1. Therefore, the sunshade curtain 32 can be smoothly wound or unwound between the take-up and extended positions when being operated.

Specifically, the connecting shaft 41 that is inserted in the base 51 frictionally contacts the base walls 511. After the fastener 52 engages threadedly with the base walls 511, the connecting shaft 41 is clamped between the base walls 511. Hence, during movement of the pull rod 33, the friction resistance force between the connecting shaft 41 and the base walls 511 has to be overcome so that the connecting shaft 41 is able to be concomitantly rotated with the guide wheels 42. When the sunshade curtain 32 is extended to any desired extended position by pulling the pull rod 33, after the pull rod 33 is released, the pull rod 33 is stopped together with the sunshade curtain 32 at the desired extended position because a retracting force of the winding shaft 31 is less than the friction resistance force between the connecting rod 41 and the base walls 511, thereby achieving the pull and stop function with relative ease. In addition, because of a frictional contact existing between the guide wheel 42 and the guide rail 12, the frictional force generated therebetween can resist the retracting force of the winding shaft 31 as well, so that the sunshade curtain 32 can be maintained at any desired extended position.

Referring to FIGS. 8 and 9, the second preferred embodiment of a sunshade assembly according to the present invention is shown. The second preferred embodiment has a structure similar to that of the first preferred embodiment except that the rolling surface 421 of each of the guide wheels 42 has the guide groove 422, and that the guide surface 121 of the corresponding guide rail 12 protrudes into the guide groove 422. Specifically, the guide surface 121 of the guide rail 12 has a protrusion 123 of trapezoidal cross section, and the guide groove 422 of the corresponding guide wheel 42 is a trapezoidal groove conforming to the protrusion 123. In actual implementation, the protrusion 123 of the guide rail 12 and the guide groove 422 of the guide wheel 42 may be configured to have other shapes, such as complementary trapezoid contours, complementary V contours, complementary U contours, and complementary saw-toothed contours, as long as they mesh with each other. In use, an engagement design of the guide rail 12 and the guide wheel 42 provides the frictional resistance force, and reduces noise.

To sum up, by virtue of the engagement design of each of the guide rails 12 and the corresponding guide wheel 42, the connecting shaft 41 connected to the guide wheels 42 can be smoothly rotated so as to prevent the guide wheels 42 from being stuck in the guide rails 12 due to a noncentral pulling force. Therefore, the sunshade curtain 32 can be smoothly wound and unwound, thereby increasing convenience to users. Furthermore, according to a design of the resistance unit 5, the base 51 provides the connecting shaft 41 with the resisting force so that the pull rod 33 can be stopped immediately when the pulling or pushing force is released and so that the sunshade curtain 32 can be pulled and stopped at any desired extended position.

While the present invention has been described in connection with what are considered the most practical and preferred embodiments, it is understood that this invention is not limited to the disclosed embodiments but is intended to cover various arrangements included within the spirit and scope of the broadest interpretation so as to encompass all such modifications and equivalent arrangements. 

What is claimed is:
 1. A sunshade assembly, comprising: two spaced-apart mounting seats; a winding shaft mounted rotatably between said mounting seats; a sunshade curtain extendably wound around said winding shaft; a pull rod connected to one end of said sunshade curtain that is distal from said winding shaft; two guide rail units, each of which includes a guide rail, said guide rail having a guide surface extending along the length of said guide rail; a link unit including a connecting shaft mounted rotatably to said pull rod and having two opposite ends, and two guide wheels respectively attached to said two opposite ends of said connecting shaft, each of said guide wheels having a rolling surface to roll on said guide surface of one of said guide rails, one of said rolling surface and said guide surface having a guide groove, the other one of said rolling surface and said guide surface protruding into said guide groove; and a resistance unit including a base mounted to said pull rod and frictionally contacting said connecting shaft to provide a resisting force against rotation of said connecting shaft.
 2. The sunshade assembly as claimed in claim 1, wherein said guide surface has said guide groove, and said rolling surface protrudes into said guide groove.
 3. The sunshade assembly as claimed in claim 2, wherein said guide groove is designed by an arcuate groove-defining wall surface.
 4. The sunshade assembly as claimed in claim 1, wherein said link unit further includes two resilient press members respectively and resiliently pressing said guide wheels against said guide surfaces of said guide rails.
 5. The sunshade assembly as claimed in claim 4, wherein said base includes two spaced-apart base walls, and a connecting wall that interconnects said base walls and that cooperates with said base walls to define an open channel, said open channel having an insert portion proximate to said connecting wall, and an open portion distal from said connecting wall, said connecting shaft being inserted through said insert portion and being sandwiched between said base walls.
 6. The sunshade assembly as claimed in claim 5, wherein said insert portion has a configuration substantially corresponding to that of said connecting shaft.
 7. The sunshade assembly as claimed in claim 5, wherein said pull rod is a hollow rod, said resistance unit being disposed inside said hollow rod, said resistance unit further including a fastener to secure said base to said pull rod, said fastener being configured as a bolt that extends through said pull rod and that engages threadedly said base walls at portions distal from said connecting wall.
 8. The sunshade assembly as claimed in claim 7, wherein each of said guide rail units further includes an elongate frame of substantially U-shaped cross section, said frame having a main wall, and first and second sidewalls extending transversely and respectively from two opposite ends of said main wall towards the other one of said guide rail units, said guide rail being disposed on said first sidewall, each of said resilient press members including two bracket plates that are sleeved onto said connecting shaft on two opposite sides of a corresponding one of said guide wheels, a connecting section that interconnects ends of said bracket plates between a corresponding one of said guide wheels and said second sidewall, and at least one resilient abutment section that is curved outwardly from said bracket plates in proximity to said connecting section and that presses resiliently said second sidewall so that said corresponding one of said guide wheels is pushed against said guide surface.
 9. The sunshade assembly as claimed in claim 1, wherein said rolling surface has said guide groove, and said guide surface protrudes into said guide groove.
 10. The sunshade assembly as claimed in claim 1, wherein said guide surface has a protrusion of trapezoidal cross section, and said guide groove is a trapezoidal groove conforming to said protrusion. 